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This study was conducted to choose the best species for plantation on a poor drainage soil in southern coast of Caspian Sea, Iran. Nutrient concentrations in live and senescent leaves and soil properties were compared among Alnus subcordata C.A.Mey (N-fixing tree), Populus deltoides­ Marsh. (Non N-fixing tree)and Taxodium distichum (L.) Rich. (Coniferous tree) plantations. In each of these plantations and an adjacent natural forest, six 20×20m plots have been selected according to a 100m × 100m randomly systematic grid. Leaf samples of green trees were collected from the bottom one-third of the tree crown by clipping two small twigs located on opposite sides of the crown (six representative trees were sampled in each plot). Senescence leaves have been collected inside wooden trap-based in each stand. Results revealed different effects of species on soil nutrients. Alnus subcordata increased soil N (%) whereas Populus deltoides­ and Taxodium distichum reduced it.The results of nutrition, litter quality, retranslocation and soil properties indicated that Alnus improve soil quality in comparison with the two others.

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The impact of climatic variations on basal area growth of basswood (BA) (Tilia americana L.), American beech (BE) (Fagus grandifolia Enrh.), bitternut hickory (BH) (Caria cordiformis (Wang.) K. Koch), largetooth aspen (LA) (Populus grandidentata Michx.), red maple (RM) (Acer rubrum L.), red oak (RO) (Quercus rubra L.), sugar maple (SM) (Acer saccharum Marsh.), and white ash (WA) (Fraxinus americana L.) was studied in a southern province of Quebec, Canada (45o 25 ’ N, 73 o 57 ’ W). In total, forty-eight climatic variations of precipitation (P) (13 variables), temperature (T) (13 variables), heat index (H), (11 variables), and evapotranspiration (11 variables) from the current (C) and past three years (P1, P2, & P3) were tested in regression models to find the best model of the relationship between those independent variables and the last ten years (1985-1994) of basal area growth of the species. Simple individual linear and second degree, mixed, and combination of multiple regression models were used to develop the best regression model for each tree species, separately. The best models explained 79% , 80% , 99% , 91% , 71%, 99% , 49% , and 98% of the total variance of the growth in BA, BE, BH, LA, RM, RO, SM and WA, respectively. The growth in BH, LA, RM, RO, SM, and WA were more associated with the previous year’s climatic variations rather than the current year’s. Bitternut hickory, LA, RM, SM, and WA growth were more related to the first year rather than the second or third preceding year variables. The June heat index of the third previous year of variables explained only 7% of the growth of white ash. It was concluded that the impact of climatic variables on tree growth may vary and may depend on the species and other unknown variables. Also, the results suggested that the first and second previous climatic variables have an important role on the growth of some species. American beech, BH, RO, and WA seem to be a good species to use for the study in dendrochronological and dendroclimatological studies.

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The effects of plant growth promoting rhizobacteria (PGPR) on growth and physiological characteristics of seedlings Corylus avellana were determined in a forest nursery. For this purpose, in a completely randomized design (CRD) and four replicates, three putative bacteria, including Pseudomonas putida, Bacillus subtilis and Enterobacter cloacae, as alone and mixed, were examined. The greatest height (26.88 cm), collar diameter (7.11 mm), leaf area (23.87 cm²)net photosynthesis (17.23μmol CO₂ m⁻²s⁻¹), transpiration rate (3.22 mmol H₂O m⁻²s⁻¹­(, stomatal conductance (0.189 mol CO₂ m⁻²s⁻¹), water use efficiency (5.33 μmol CO₂ mmol⁻¹  H₂O) and chlorophyll content (26.16 SPAD) allocated to seedlings inoculated with a combination of three bacteria. The greatest root dry weight (3.98 g), root volume (10.87 cm³), total plant dry weight (9.91g) was detected in seedlings inoculated with P. putida. In total, for the beneficial effects of PGPR on growth and physiological traits of C. avellana seedlings, all three bacteria either as individual or as mixed were found suitable for seedling inoculation. In fact, it is affirmed that inoculation of root with PGPR can be a proper approach to produce healthy and strong seedlings in nursery.

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Background: Seed energy and seed vigour are the most important qualitative attributes influencing plant’s growth and establishment that can be improved by techniques generally known as seed priming, which enhances the percentage, speed and uniformity of germination. Effect of various priming techniques was conducted on seed germination and seedling’s early growth of elder pine (Pinus eldarica Medw.) in Seed Technology Lab of Natural Resources Faculty, Tarbiat Modares University, Iran.
Materials and Methods: Seeds were treated through hydropriming with distilled water, halopriming with NaCl at -4 and -8 bar concentrations, osmopriming with polyethylene glycol 6000 (PEG 6000) at -4 and -8 bar concentrations and hormonopriming with salicylic acid (SA) at 1 and 2 mM solutions for 48 h. Un-primed dry seeds were taken as control. The seeds were kept in germinator at 20 ± 0.5 ^°C, 65% relative humidity and 16.8 h light/dark photoperiod for 42 days.
Results: The highest germination percentage (92%) and germination speed (5.13 seeds/day) were obtained with hydropriming. The best results to improve germination energy, time to 50% germination, seedling length, seedling dry weight and seedling vigour index were achieved with hydropriming and hormonalpriming 1 and 2 mM. Osmopriming and halopriming -8 bar compared to control in most mentioned traits showed poor performance.
Conclusions: Hydropriming and hormonalpriming can be suitable techniques to support nursery practices of elder pine seed in order to improve germination percentage, emergence and early seedling growth.

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Aim This investigation aims to study the effect of biochar on gas exchange, water relations and photosynthetic pigments of European yew (Taxus baccata) seedling in different light intensities (LI).
Materials and Methods Two-year potted seedlings of European yew are placed in forest stands with canopies of closed (15% LI), semi-closed (45% LI) and open (75% LI). In late June 2018, biochar was added to potted soils at the levels of zero, 10, 20 and 30 g.kg^-1 and until the end of November, every 3 (or 4) days 100 mL water was given to each pot.
Findings Seedling survival at different levels of treatments was 100%. Regardless of biochar, the highest photosynthesis, stomatal conductance, intercellular CO₂ concentration, relative water content, chlorophyll (chl) contents in closed canopy, and the highest leaf temperature in open canopy was observed. With increasing biochar concentration, chl b and total chl increased (28-86%, respectively) in open canopy and decreased (28 and 28%, respectively) in closed canopy. Neither biochar nor LI affected significantly electrolyte leakage and carotenoid content.
Conclusion Although yew seedlings were able to maintain their vegetative quality and health in different LI, and the measured variables responded differently to light-biochar combination, it may be best to grow yew in shade together with biochar. Since, the effect of biochar becomes more tangible over time, further research in next years can lead to more accurate findings affected by the combined light-biochar treatment.

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Abstract:
Aim: With global warming and limited water resources in the world, especially in arid lands of Iran, managing the production of forest seedlings in the country's nurseries is facing a special challenge. In this regard, the study of drought tolerant plants to select them in the mass seedling production programs can be useful.
Material and methods: Potted seedlings of Persian oak (Quercus brantii Lindl.), pistachio (Pistacia atlantica Desf.), Judas-tree (Cercis siliquastrum L.) and black poplar (Populus nigra L.) exposed to a normal irrigation scheme (100% field capacity) and drought-stressed (30% field capacity) conditions were examined over a period of 120 days in a greenhouse of Bam Khorramabad Nursery to judge their tolerance for drought stress.
Findings: Drought-tressed seedlings from all species had a lower content of chlorophyll a, chlorophyll b, total chlorophyll and carotenoids compared to the control plots, but the content of proline and malondialdehyde (MDA) did, however, increase. Under stress conditions, MDA content in black poplar, Judas-tree, Persian oak and pistachio was 174, 121, 105 and 102% higher than the control seedlings, respectively, and this increase in black poplar over other species ranged from 93.5 to 176.5%.
Conclusion: This study confirms that among four tree species, black poplar has lowest tolerance to drought stress. Thus, Persian oak, pistachio and Judas-tree, should be prioritized in the mass seedling production programs of nurseries in arid areas suffering from limited water resources, due to their higher tolerance to water scarcity.

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Aim: Caspian locust, native to Hyrcanian forests of Iran, is one of the pioneer species, which it distributed in the moist soils of these forests. So far, the response of its seedlings to permanent and temporary flooded beds has not been reported. This study was conducted with the objective to analyze the physiological responses of Caspian locust seedlings to flooding and flooding-recovery conditions.

Materials & Methods: Flooding conditions were examined for 90 days in the greenhouse of the Tarbiat Modares University. The study was carried out in a factorial experiment as a completely randomized design with 5 treatments and 4 replications. Treatments included: (1) continuous flooding for 90 days (F90), (2) flooding for 60 days followed by a 30-day recovery (F60+R30), (3) flooding for 45 days followed by a 45-day recovery (F45+R45), (4) flooding for 30 days followed by a 60-day recovery (F30+R60) and (5) Control.
Findings: Results showed that flooding for 90 days induced a significant decrease in net photosynthesis (-91%), stomatal conductance (-77%), transpiration (-81%), Chl a (-63%), Chl b (-67%) and Chl _Tot (-64%) compared to the control (p<0.05). When flooding was removed for 30-60 days, plants were able to recover gas exchange activities from 30 to 90% and Chl content by 55-90%.
Conclusion: Based on our results, seedlings of G. caspica can survive and grow throughout a medium period of soil waterlogging. Therefore, Caspian locust appears to be a promising species for reforestation programs in the riverine areas and temporarily flooded wetlands.
 

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Abstract
Aim: Common yew (Taxus baccata L.) is one of the endangered species in Iran. Considering the prospect of climate change and global warming in the coming years, research on the tolerance of its seedlings to drought stress can be useful.
Materials & Methods: This research was conducted on four-year-old common yew potted seedlings. For this purpose, the effect of drought stress (100% and 30% of field capacity (FC)) on growth and physiological traits of common yew seedlings was carried out in a completely randomized design with three replications for 6 months. Findings: The results showed that survival, shoot growth and root diameter growth of seedlings did not change under water deficit, but a significant negative effect in most of the physiological variables (except for stomatal conductance) was found under the stress (30% of FC); so, the activities of photosynthesis, transpiration, mesophyll conductance and water use efficiency decreased by 68.3%, 23.9%, 69.6% and 57.9%, respectively; On the contrary, intercellular CO₂ increased by 4%.
Conclusion: It can be concluded that the growth traits of yew seedlings were not affected by water scarcity in the first year of growing season, due to the slow-growth nature. Since, common yew seedlings need several years of care in the nursery to prepare for the transfer to the natural field, it is recommended to manage the seedlings in well-watered conditions for a better response of physiological traits and more favorable growth in the coming growing years.
 

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We assessed the size and composition of the soil seed bank and above-ground vegetation in 52 relevés representing a range of habitats within an old- growth, temperate deciduous forest at Hyrcanian region, northern Iran. We identified 63 taxa in the seed bank, with an average density of 4202 seeds/spores per m2 by seedling emergence method. Hypericum androsaemum, Cardamine impatiens, and Rubus hyrcanus, with Athyrium flix- femina and Pteris cretica as two ferns, were the most abundant species in the seed bank and spore bank that made up to 92 % of the seeds/spores recorded in the soil seed bank. Totally, 107 species were recorded in the vegetation and soil seed bank of the study site, of which 33 % were common in both seed bank and vegetation and 26 % and 41 % were found only in the seed bank or in the vegetation, respectively. The dominant tree species with many woody understory species found in the above- ground vegetation were absent from the persistent soil seed bank. Jaccard’s similarity coefficient revealed that the correspondence between the species in the vegetation and the same species in the seed bank were consistently low (average of 24.3%) based on presence/absence data. Yates- corrected c 2 test showed that sites present significant differences (P<0.001) in seed bank and vegetation species composition. DCA ordination of the above-ground vegetation and soil seed bank flora displays a clear pattern, with two distinct groups on the basis of the above-ground vegetation and soil seed bank floristic data. Our results explain the low similarity between soil seed bank and vegetation of the Darkola oriental beech (Fagus orientalis Lipsky) forest only to a limited extent, but confirm that most of the species of the above-ground vegetation do not depend on the persistent soil seed bank. Therefore, it may be concluded that the persistent soil seed bank is not capable of restoring the extant vegetation of the studied site.

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This paper studies the consensus problem of nonlinear leader-following multi-agent systems (MAS). To do this, the error dynamics between the leader agent and follower ones are described via a Takagi-Sugeno (TS) fuzzy model. If the obtained TS fuzzy model is stable, then all of the nonlinear agents reach consensus. The consensus problem is investigated based on the parameterized or fuzzy Lyapunov function combined with a technique of introducing slack matrices. The slack matrices cause to decouple the Lyapunov matrices from systems ones and therefore, sufficient consensus conditions are obtained in terms of linear matrix inequalities (LMIs). The proposed slack matrices add an extra degree-of-freedom to the LMI conditions and also decrease the conservativeness of the LMI-based conditions. Finally, in order to illustrate the effectiveness and merits of the proposed method, a numerical example for the consensus problem of nonlinear leader-follower MAS with thirteen followers is solved.

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Background and Aim: Yogurt is one of the most popular dairy products that is widely consumed around the world, which has received much attention due to its high nutritional value and economic importance. Therefore, in this study, by considering different indicators, in order to improve the nutritional properties of yogurt and produce products with desirable and uniform quality, by adding essential oils to control acidity, prevent and cover the acidity over time and also achieving antioxidant properties.
Methods: In this study, after preparing probiotic yogurts containing saffron, thyme and black cumin essential oils at four levels (0, 0/5, 1 and 2), physicochemical properties (PH, acidity, color, hydration and viscosity) and sensory properties were studied in a completely randomized manner in three replications over 21 days.
Results: The results of the evaluations of this study showed a significant effect of independent variables and also their synergistic effect at the level of 0.5% on the properties of yogurt. In the study of color parameters, it was observed that the brightness decreased with increasing the concentration of essential oil so that the control sample had a higher L* index, also a* and *b index increased with increasing essential oil concentration. The increase in b* index was more due to the presence of carotenoid pigments in saffron essential oil. The pH changes of yogurt treatments were completely affected by microbial growth in the treatments, which significantly reduced and increased the acidity over a period of 21 days (P ≤ 0.05).
Conclusion: Enrichment of probiotic yogurt formulated with essential oil can be a good option in improving the functional properties of the final product and enhancing its antioxidant   properties.

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Enzymatic treatment of wheat flour is an interesting function to improve its functional properties. Because enzymes with different biochemical activities can have synergistic effects on dough behavior or product quality, the individual use and combination of enzymes used in bread production processes is important today. The aim of this study was to evaluate the synergy of glucose oxidase and lipase enzymes in physicochemical properties of barberry flour and bread formulated with relative replacement of corn flour. Treatments in 7 groups (T0 control sample, T1 containing 5% corn flour 0.05% glucose oxidase 0.05% lipase, T2 containing 10% corn flour 0.07% glucose oxidase 0.07% lipase, T3 containing 15% flour Corn 0.09% glucose oxidase 0.09% lipase, T4 contains 20% corn flour 0.011% glucose oxidase 0.011% lipase, T5 contains 25% corn flour 0.13% glucose oxidase 0.13% lipase, T6 Containing 30% corn flour (0.15% glucose oxidase (0.15% lipase) were prepared).
 The chemical results of the treatments showed an increase in moisture, ash and gluten index so that the highest amount of the mentioned factors was observed in T6 sample. Zellini number, phallus number, protein and gluten showed a significant decrease.  Farinograph test results showed no significant water uptake, reduced spreading time and resistance with increasing corn flour replacement percentage in the treatments. The tensile strength of the treatments in the extensograph test showed an increase and a decrease in tensile strength and tensile strength of the treatments, respectively (p<0.05).
 Histological results showed that the use of lipase enzyme and corn flour reduces the stiffness of the treatments. While the addition of corn flour caused the doughs to stick and the enzymes were ineffective. The elasticity of the doughs was also improved by the addition of glucose oxidase. The results of sensory evaluation introduced T4 treatment as the superior treatment.

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Nowadays, conversion industries with the objective of reducing production costs in the country are of great importance. On one hand, considering the high amount of waste after poultry slaughter in Iran, on the other hand, there are a lot of evidences related to the beneficial effects of hyaluronic acid on human health, especially in the treatment of joint diseases such as osteoarthritis. Many efforts have been carried out to make the best usage of these wastes. Therefore, the purpose of this study was to obtain the hyaluronic acid from rooster comb tissue with suitable physicochemical and rheological properties to enrich various foods, including dairy products. In this research, after the initial preparation of rooster comb tissue, hyaluronic acid was extracted through three methods using ultrasound waves-ethanol, physiological serum- acetic acid and physiological serum-ethanol solvents. Then, the physicochemical and rheological attributes of the acquired hyaluronic acid were evaluated. Based on findings, the highest content of extracted hyaluronic acid (4.2 mg/g) was determined in the presence of physiological serum-ethanol solvents (P<0.05). Also, the hydrocolloid was extracted through the mentioned method, had the highest brightness (23.74) and the lowest pH (6.76) and density (810 kg/m³) (P<0.05). However, the influence of different extraction methods on viscosity was insignificant (P>0.05). Hence, the results of the present study showed that the physiological serum-ethanol are an appropriate solvents for extracting and purifying hyaluronic acid, which could be used as a functional food additive.

 

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In this study, the effect of nanoparticles on oxide at three levels of 1, 3 and 5% was added to polylactic acid and chitosan nanocomposites and the results of its SEM (electron microscope) evaluation were evaluated and showed films containing polylactic acid and chitosan. It had an irregular and compact structure and with the addition of nanoparticles on oxide, it had a regular and cohesive structure. And water vapor permeability showed a significant effect (P <0.05). The results of histometry showed that with increasing the concentration of nanoparticles, the tensile strength of the film and the nanocomposite coating was significantly lower than the control treatment (P <0.05). Also, large changes in length to break point did not show a statistically significant difference. The results of tissue stiffness of this study also showed that during the 15-day storage time, the test treatment had the highest amount of stiffness. The effect of film and coating of nanocomposites based on polylactic acid and chitosan containing nanoparticles on zinc oxide on microbial properties indicated that during the shelf life of bread containing polylactic acid and chitosan dimers has an inhibitory effect on fungal growth by increasing nanoparticles on zinc oxide. Increases significantly. It also showed that the shelf life of seven sliced ​​toast containing the mentioned variables was higher at 5% level compared to the control treatment.
 

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Olive oil is a unique edible oil that has attracted attention due to its high levels of monounsaturated fatty acids, pleasant taste, good stability, and special health benefits. In this study, the quality of virgin olive oils from the Arbequina, Mari, Shengeh, and Zard cultivars in the Tarem region was investigated, and the parameters of sterols, acidity, peroxide value, and iodine value were evaluated. Gas chromatography was used to determine and identify the sterols. The results showed that the amount of sterols in virgin olive oils from the Arbequina, Shengeh, Zard, and Mari cultivars differed significantly at the 5% level. The most abundant sterols found in all cultivars were beta-sitosterol, delta5-avenasterol, and campesterol. The free acidity level in the Mari cultivar had the highest amount, while the Arbequina cultivar had the lowest amount. The highest peroxide value was observed in the Zard cultivar, while the lowest was observed in the Mari cultivar. Finally, it can be concluded that the quality parameters evaluated for the Arbequina, Shengeh, Zard, and Mari cultivars were within the allowable standard range, and there was no significant difference in quality among these cultivars.
 

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In this research, cress seed gum in three concentrations (0.1, 0.2 and 0.3%) as a stabilizer and egg white powder in four levels (1, 2, 3 and 4%) was used to produce orange juice foam and then the optimal foam sample (minimum density, maximum stability and overrun) was selected. Next, the optimal sample for drying by foam mat drying method was dried at three different temperatures (40, 55 and 70 C) by hot air dryer. The results showed that by decreasing the concentration of cress seed gum and increasing the concentration of egg white protein, the overrun increased significantly and the density decreased (p<0.05). Also, by increasing the concentration of cress seed gum and egg white protein, the stability of the foam improved. Among all the treatments, the sample containing 4% egg white powder and 0.1% cress seed gum, in addition to low drainage (drainage volume 0.5 ml), has low density (0.321 gr/cm) and high overrun (308 percent) which was selected as the best treatment for the production of orange powder. The drying time of orange pulp at temperatures of 40, 55 and 70 degrees Celsius was 100, 150 and 280 minutes, respectively. The effective diffusion coefficient in the temperature range of 40 to 70 degrees Celsius was in the range of 1.38 x 10-7 to 2.938 x 10-7 m2/s. The results showed that by increasing the temperature from 40 to 70 degrees Celsius, the solubility of the powder increased, while the water activity of the powder, density and reabsorption of water decreased significantly (p˂0.05). Also, the results of color analysis showed that with increasing drying temperature, color indices (L*) and (a*) increased significantly and color index (b*) decreased. Our results showed that food powders with good properties can be gained by foam mat drying.
 

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The moment-resisting steel frame building is highly used due to their advantages such as, high speed construction coupled with appropriate strength and ductility. The main advantage of this system is related to architectural considerations and the possibility of creating openings within all spans. Connections play an outstanding role in the seismic responses of this structural system. The connections are generally assumed to have a rigid behavior in analyzing and designing of the moment-resisting steel buildings. Studying of the previous investigations indicates that the assumption of rigid behavior for the beam-to-column connections is not always correct and can bring about a significant error in the responses. In this study, behavior factor of moment-resisting steel frames considering joint flexibility is evaluated. To do so, some intermediate moment-resisting steel frames with various number of stories and bays including 1-bay, 1- and 2-story frames, 2-bay, 2-, 4-, 6-, 8-, and 10-story frames, 3-bay, 3-, 6-, 9-, and 12-story frames and 4-story, 2-, 6-, 10-, and 14-story frames are designed regarding Iranian seismic code and Iranian national building code for designing steel structures. After that, the capacity curves of these frames are achieved using pushover analysis once considering rigid connections and again taking joint flexibility into consideration using OpenSees software. To model the nonlinear behavior of connections, one zero-length rotational spring is assigned to each end of beam members. Then, the behavior factor of each frame is calculated using the recommended procedure of FEMA-P695. The outcomes show that for the frames with rigid connections, the acquired behavior factors are almost close to 5 (which is the prescribed behavior factor in Iranian seismic code for the intermediate moment-resisting steel frames). Furthermore, for the frames with semi-rigid connections (60%), the behavior factors are close to 5 as well. For 10-story 2-bay, 12-story 3-bay, and 14-story 4-bay frames the prescribed behavior factor in Iranian seismic code does not meet. For these frames, the ratio of height to total-span that is known as the slenderness coefficient of the frame is higher than others, so these frames fall into slender frames. Results show that for the frames with semi-rigid connections (60%), despite of decreasing the over-strength factors in some cases, their ductility increased, therefore, the behavior factors are achieved higher than those of the frames with rigid connections. All in all, it is observed that the nonlinear behavior of connections can significantly affect the seismic behavior of the moment-resisting steel frames. Comparing the behavior factors calculated in this investigation with the prescribed value of this factor in code 2800 showed that for the frames with rigid connections, 80% of the obtained behavior factors are higher than 5. For frames with semi-rigid connections (80% and 60%), 0%, and 66% of the behavior factors meet the proposed value of code 2800, respectively. Regarding the observations, it is recommended that the influence of joint flexibility be considered in assigning a value of behavior factor to design the moment-resisting steel frames.    
Keywords: rigid connections, semi-rigid connections, moment-resisting steel frame, nonlinear static analysis, distributed and concentrated plasticity models